Vapor electric apparatus.



R. C. HEWT.

VAPOR ELECTRIC APPARATUS.

APPLICATION FILED oc. I, 1912.

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UNITED STATES PATENT OFFICE.

PETER COOPER HEWITT, OF RINGWOOI) MANOR, NEW JERSEY, ASSIGNOR, BY MESNEASSIGNMENTS, T I COOPER' HEWITT ELECTRIC COMPANY, OF HOBOKEN. NEWJERSEY, A CORPORATION OF NEW JERSEY.

VAPOR ELECTRIC APPARATUS.

Specification of Letters Patent.

Patented Julie 19, 1917.

Application led October 1, 1912. Serial No. 723,303.

To all whom t may concern.'

Be it known that I, Parnu COOPER Hnwrr'r, a'citizen of the UnitedStates, and resident or Rinvwood Manor, county of Passaic,

State or New Jersey, have invented certain new and useful Improvementsin Vapor Electric Apparatus, of which the following is a specification.U

This invention relates to vapor electric apparatus of the vkindcomprising an exhausted container or envelop provided with positive andnegative electrodes insulated from each other with reference to thewalls of the container, the negative electrode being composed ofmaterial of such a nature that the'particles thereof will reunitephysically and electrically on contact with one another after separationunder the conditions obtaining within the container.

The invention more particularly relates to rectitying apparatus of theabove general character which is adapted to operate with large currentsof the character utilized in commercial service.

The general nature and operation of apparatns of this character is nowwell known and more particularly the fact that a characteristic dropofelectric potential in mercury vapor apparatus occurs between thepositive and negative terminals of the apparatus which may be equal inamount to about fourteen volts when the resistance of the vapor columnis but small.

I have found that the drop of potential above referred to may be dividedinto three main component parts located respectively at the surface ofthe positive electrode, within the luminous vapor column and in theregion adjacent to the surface of the negative electrode.

I have further discovered that the last of these three components can befurther subdivided into three portions, namely, a drop of potential atthe actual surface of the negative electrode, a drop of potentialsomewhat uncertain in nature and amount within a region of which thenegative ame or are is y umn is eliminated.

The present invention contemplates a new disposition of the positiveelectrode with reference to the negative electrode and to the variousregions in which falls of potential occur, as has been above described,and my invention consists essentially in placing the positive electrodein such proximity to the negative electrode that the positive electrodeis within the region in which, what I have termed above the negativeelectrode component or' the fall of potential, occurs, so that theluminous portion of the vapor col- As the result of this arrangement arelatively great reduction in the tota-l fall of potential between thelterminals of the apparatus is eii'ected which can be accounted for bycertain of the reactions above referred to being eliminated or annullingone another.

The invention is illustrated in the acconr panying drawings, of whichFigure l is a sectional view in side elevation showing one form of vaporelectric apparatus embodying the invention.

Fig. 2 is a plan view partly sectional on the line II-II of Fig. l.,viewed from above; Fig. 3 being a similar view from below.

Fig. 4 is a pla-n view of the positive electrode of the apparatus shownin Fig. l, viewed from below.

Referring now to the drawings, the rectit'ying apparatus comprises acylindrical metal container l, of steel, Norwegian iron or othersuitable material, the base portion 2 of which serves as the receptaclefor the mercury or other vaporizable liquid conducting materialindicated at 3, which constitutes the negative electrode of theapparatus. The top of the container 1 is closed by a composite covercomprising a flanged ring i of mild steel or other suitable materialsupported upon an annular rib 5 secured to the upper portion of thecontainer l. The ring 4c supports an annular disk 6 having a lowerprojecting portion 7 the outer edge of which is beveled to correspondwith the inner edge of the ring e. The disk 6 is also provided with anupwardly extending cylindrical portion 8 the outer surface o-f' which isscrew-threaded. Upon the disk 6 an insulating bushing 9 oi porcelain orother suitable nonconducting material is' supported, a beveled shoulderupon which is arranged to be clamped firmly in engagement with the disk6 by means of a the insulating ring 9. The positive electrode 12 isarranged to be water-cooled, being provided withan internal su )ply pipe16 the lower portion of which is oli cup-shaped form located within thecorresponding portion 13 of the positive electrode 12. The lower edge ofthe cup-shaped ortion of the supply pipe 16 is provided wit two or morenozzles as shown clearly at 17in Fig. 4, these nozzles being so arrangedthat the cooling liquid passing through the supply pipe 16, as 1ndicatedby the arrows in Fig. 1, has a tangential motion imparted thereto whenissuing from the nozzles 17y into the interior of the positive electrode12. The cylindrical portion 14 of the latter is provided with an outletpipe 18 for the cooling water, which may be caused to circulate throughthe hollow electrode 12 by any suitable means, such as a pump. The lowerportion 2 of the metal container 1 containing the negative electrode isalso surrounded by a cooling jacket 19 provided with inlet and outletpipes 20, 21 respectively. l

Located within the space between the positive electrode 12 and thenegative electrode 3 is a cooling device 22 comprising a hollow circularcasing of convex form, to one edge of which cooling liquid is suppliedthrough a pipe 23, an outlet pipe 24 at the opposite edge of the coolingdevice 22 being arranged to project within the hollow casing to a pointnear the upper inner surface of the latter, as

'clearly shown in Figs. 1 and 3. The pipes 23 and 24 are passed throughthel container 1, a tight joint being insured by any suitable packing.An insulating shield 25 is provided, the lower edge of which is belowthe surface of the negative electrode 3, this shield being held inposition by suitable clips 26 and serving to limit the active area ofthe negative electrode in a manner now well known in the art. Anauxiliary or starting positive'electrode 27 is also provided, comprisinga horizontal tubular portion 28 projecting through a suitable gastightbushing 29 in the wall of the cooling jacket 19 and a tubular arm 30extendingat right-angles from the portion 28 and terminating in a solidcontact member 31. The portions 28 and 30 of the starting electrode aresurrounded by a tubular cooling jacket 32 preferably of quartz or otherrefractory material, the cooling liquid for this electrode passingthrough the tubular member 28,0011- stituting the conducting portion ofthe electrode and from thence through a hole in the tubular arm 30 intothe interior of the quartz jacket 32, the outer end of which is in opencommunication with the cooling jacket 19 for the negative electrode.

r1`he operation of the starting electrode will be readily understoodwithout further description, as by rotatin the horizontal portion 28 ofthe electrode rom the exterior of the apparatus the solid contactmember' 31 can be brought into engagement with the surface of thenegative electrode within the insulating shield 25, the rotation in theopposite direction serving to withdraw the contact member 31 from thenegative electrode and initiate a discharge within the container of theapparatus.

As will be seen from Fig. 1 of the drawings, the positive electrode 12is located much nearer to the negative electrode 3 than has `hithertobeen customary, so that as explained above the positive electrode willlie within a certain critical distance of the negative electrode,resulting in a considerably greater rcduction in the total .fall ofpotential between the terminals of the apparatus.

1t is unnecessary to determine or describe i'ully the exact theory uponwhich this reduction in the total potential depends, but it is found inpractice undoubtedly to occur' when the positive electrode is placedmuch nearer to the negative electrode than is usual in apparatus of thisdescription using small currents, the exact distance separating the twoelectrodes being dependent upon the amount of current traversing theapparatus and the degree of rarefaction of the vapor. The .intermediatecooling device 22 also serves to modify the distance necessary betweenthe positive and negative electrodes, the general tendency of thecooling effected in this manner being to increase this distance.

It should be noted that the reduction in the fall of potential abovedescribed is not due to a reduction in the length of the vapor column,since, if the electrodes be gradually moved toward one another the fallof potential between the terminals of the apparatus remain substantiallyconstant until the positive electrode is within a certain criticaldistance of the negative electrode which distance varies as abovestated. When this critical distance is reached a sudden marked decreasein the fall of potential across the terminals of the device occurs andthe luminous effect of the vapor column disappears.

As an example of the actual reduction in the fall of potential obtainedaccording to this invention I may mention that in a particular apparatusthe normal drop of potential across the terminals was fourteen volts,and by reducing the distance between the positive and negativeelectrodes to the critical distance above referred to the drop ofpotential suddenly decreased to somewhat less than eight volts.

- By utilizing this reduced fall of potential a corresponding decreaseinthe total energy lost in the apparatus is obtained.

It will be understood that the inventionV is not limited to anyparticular type of electrede nor to any specific proportions or locationof the electrodes relatively to one another and that all arrangements inwhich the electrodes are so disposed as to utilize the decreased fall ofpotential above indicated fall within the scope of the invention.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, l. declarethat what l claim is- 1. A vapor electric apparatus comprising anexhausted container, positive and negative electrodes therein, theextremity of the positive electrode being located at a critical distancefrom the negative electrode, the said critical distance bein thedistance between the negative electro e and a point in the vapor columnat which a sudden marked decrease in the fall of potential across theterminals of the device occurs, as compared with the drop when theelectrodes are more remote from each other.

2. A vapor electric apparatus comprising an exhausted container,positive and negative electrodes therein, the extremity of the positiveelectrode being located at a critical distance from the negativeelectrode, the said critical distance being the distance loetween thenegative electrode and a point in the vapor column at which a suddenmarked decrease in the fall of potential across the terminals of thedevice occurs, and a cooling device located intermediate the twoelectrodes and serving to modify the said critical distance.

3. A vapor electric apparatus comprising an exhausted container,positive and negative electrodes therein, the positive electrode beinglocated in proximity to the negative electrode and having a suitablestem for connection with the external circuit, a tubular device insidethe positive electrode, separated therefrom by an intervenin space, andconforming generally to the s ape of the positive electrode and its stemfor permitting the circulation of a cooling fluid, and a tube carrying acooling iluid outside the positive electrode and .passing in frontthereof.

4. A vapor electric apparatus comprising an exhausted container,positive and negative electrodes therein, the positive electrode beingcup-shaped and located in proximity to the negative electrode and havinga suitable stem for connection with the external circuit, a tubulardevice inside the positive electrode, separated therefrom by anintervening space, and conforming generally to the shape of the ositiveelectrode and its stem for permitting the circulation of a coolingfluid, and a tube carrying a cooling fluid in front of the positiveelectrode and in proximity thereto along the entire face of the saidelectrode.

5. ln a vapor electric apparatus comprising an exhausted container,positive and negative electrodes therein, an insulating shield withinthe negative electrode for limiting the active area thereof, incombination with starting devices for the said apparatus, comprising aconductor sealed through the Wall of the apparatus and bent into contactwith the negative electrode.

6. in a vapor electric apparatus comprising an exhausted container,positive and negative electrodes therein, an insulating shield withinthe negative electrode for limiting the active area thereof, incombination with the starting devices for the said apparatus, comprisinga conductor sealed through the wall of the apparatus and bent into con'-tact with the negative electrode, and a cooling jacket surrounding thestarting conductor.

Signed at New York in the county of New York and State of New York this27th day of September A. D. 1912.

PETER COOPER HEWITT.

Witnesses:

JOHN W. CRANDALL, Trios. H. BROWN.

